In 2016, the United Nations took a decisive step to protect the future of both the planet and public health. Building on the success of the 1987 Montreal Protocol, the Kigali Amendment was adopted to accelerate the phasedown of hydrofluorocarbons (HFCs), the powerful greenhouse gases widely used across multiple industries. 

The pharmaceutical industry responded by launching a search for alternatives to the HFCs widely used as propellants in pressurized Metered Dose Inhalers (pMDIs). Because pMDIs rely on propellants to deliver therapeutics, any transition would require viable, scalable alternatives. Simultaneously, pharmaceutical companies, suppliers, and regulators had to collaborate to ensure that environmental progress would not come at the expense of patient access to essential medicines. 

Ten years on from the Kigali Amendment, the transition to low Global Warming Potential (GWP) propellants in pMDIs is well underway. But as timelines tighten, the key question remains: has the industry done enough to secure a truly sustainable future for inhalation?  

A decade of industry-wide progress 
The Kigali Amendment was more than environmental policy; it was a public health commitment. By cutting HFC use, the agreement could prevent up to 0.4°C of global warming by the end of the century, making it one of the most significant climate mitigation measures ever agreed (1). Crucially, it also addressed factors that exacerbate respiratory disease, reinforcing the link between climate action and health outcomes. 

Over a decade since the Kigali Amendment, the inhalation industry and its supply chain have made a substantial collective effort, investing hundreds of millions of pounds in the green transition to low GWP propellants. However, where sustainability was once seen as desirable, it is now expected, and global climate discussions continue to highlight the scale of the task ahead. At CoP30 in Brazil in late 2025, the latest emissions gap report revealed that the world is still on course for roughly 2.8°C of warming, far beyond the Paris Agreement thresholds and deep into the zone of severe, irreversible consequences (2). 

For the inhalation industry, this means accelerating the shift to low carbon pMDIs while ensuring manufacturing capacity, supply chain resilience and regulatory readiness keep pace.  

Leadership in sustainability  
As the industry-wide shift to low GWP propellants advanced, Bespak, the specialist inhalation CDMO, evolved from a key player in the pMDI supply chain into a position of true leadership. With an aim to lead the green transition, the urgency was clear: the world would not wait, and neither would Bespak.  

Since 2024, Bespak has invested early and decisively in the capabilities required to support next-generation propellants and forged expert collaborations across the supply chain. From optimising established technologies to expanding manufacturing infrastructure, Bespak and its partners have worked tirelessly to remove barriers to adoption. 

Establishing manufacturing capacity
A major challenge for the inhalation industry’s green transition was the limited manufacturing capacity available. Bespak has played a vital role in expanding the production capacity for low carbon pMDIs, achieving the milestone of becoming the first CDMO with manufacturing capability for both low GWP propellants HFA-152a and HFO-1234ze. These investments are helping to close a critical capacity gap and give pharmaceutical partners confidence that supply can scale in line with growing demand. 

By investing early in deep technical expertise and purpose-built manufacturing infrastructure, Bespak has positioned itself to support partners through reformulation, scale-up and commercialisation, helping to ensure that low carbon pMDIs can reach patients without delay. 

Device optimisation
While the capacity gap for low carbon pMDI manufacturing is a key factor in the green transition, it was also vital to optimise components. Perhaps the most crucial of these was the pMDI valve which ensures safe and consistent dosing and protects drug formulations from moisture.  

Recognizing this, Bespak optimised its market-leading BK357 valve for use with next-generation propellants, the first of which to be approved for use with a low GWP propellant, supported by extensive feasibility data across multiple formulations. Engineered with precision, the BK357 valve is now backed by a life-cycle assessment independently validated by sustainability experts (3).  

Sustainability is also supported through Bespak’s advanced modelling capabilities, which enable virtual testing of design and formulation changes. This approach reduces the need for physical trials, cutting development time, costs and experimental waste while improving the efficiency and robustness of early-stage development.  

Strengthening supply chain resilience
Supply chain security has been another key concern, which is why Bespak has worked to localize and strengthen its UK-based pMDI supply chain. By establishing partnerships with key local industry players, including DH Industries, Orbia Fluor & Energy Materials, H&T Presspart, OzUK, and the Medicines Evaluation Unit, Bespak is ensuring a network is in place to cope with low carbon pMDI manufacturing demand. 

Combining technical capabilities, manufacturing equipment, propellant supply and clinical trial support, these collaborations have helped turn the Northwest of England into a region of excellence in pMDI development and manufacturing. This consolidation of the pMDI supply chain also helps to reduce the carbon emissions that arise from the transportation of goods between sites during the development and production process. 

A holistic approach to sustainability 
While the transition to low GWP propellants is mission critical, sustainability at Bespak extends far beyond product innovation. From the outset, the company has taken a holistic approach, embedding environmental, social and governance (ESG) considerations into how it operates and grows. 

As part of this, Bespak has received approval for its net-zero and near-term company-wide emission reduction targets with the Science Based Targets initiative (SBTi), a corporate climate action organisation (4); Bespak’s target includes an aim to reduce greenhouse gas emissions intensity by 97% by 2050. The validation of these targets marks a significant step in Bespak’s climate journey and reinforces its commitment to taking science-aligned climate action to reduce the impact of the most emission-intensive areas of its carbon footprint.  

More locally, Bespak has conducted biodiversity assessments at both of its UK manufacturing sites as well as a local needs analysis at each of its UK locations to identify how the company can contribute to the highest priorities in the community. Bespak is also working to reduce energy consumption and waste where possible through on-site solar panels and recycling initiatives. These actions reflect a commitment to environmental stewardship and social responsibility. 

Collaborating for success  
There is a clear recognition that no company can, nor should, take on the green transition alone and so, ultimately, the shift to low carbon pMDIs is defined by collaboration, trust and a shared determination to go further, faster.  

In 2025—nine years after Kigali—the first low carbon pMDI, developed by AstraZeneca, received regulatory approval (5). At Bespak, we were proud to play a pivotal role in this milestone, supplying the first-ever valve approved for use with the near zero GWP propellant HFO‑1234ze, created by our supply chain partner, Solstice Advanced Materials. 

Soon after AstraZeneca’s breakthrough, both Chiesi and GSK announced the successful completion of clinical studies in 2025, setting the stage for a new generation of carbon-minimal pMDIs to reach the market, powered by Orbia Fluor & Energy Materials’ next-generation propellant, HFA-152a (6,7). With momentum building, Bespak strengthened its commitment by expanding aerosol production capacity, reinforcing the UK’s position as a center of excellence for pMDIs as the global manufacturing base began to transition to sustainable propellants.  

Kigali set a global deadline of 2047 to reduce HFC consumption by 80–85%. A decade later, it is clear the pharmaceutical industry will move much faster. Regional legislation is already accelerating local phasedowns, and the ultimate phaseout now rests in the industry’s hands.  

The green transition is now  
Ten years on from Kigali, the industry has proven that when innovation and collaboration align, rapid progress is possible. With CDMO partners such as Bespak, the industry has the technology, infrastructure and regulatory progress needed to scale low carbon pMDIs. But the moment for action is here, and we cannot afford another decade of incremental change. Every company must accelerate development, strengthen partnerships and push forward with urgency. Now is the time for the industry to convert capability into action and momentum into meaningful change.  

References 

1. Kigali Amendment (2025) United Nations Development Programme.  

2. New climate pledges only slightly lower dangerous global warming projections (2025) United Nations Environment Programme. 

3. Bespak achieves sustainability milestone with first life cycle assessment for pressurized Metered Dose Inhaler valve (2025) Bespak.  

4. Bespak receives approval for net-zero and near-term targets with SBTi (2025) Bespak.  

5. Trixeo Aerosphere approved in the UK as first inhaled respiratory medicine using next-generation propellant with near-zero Global Warming Potential (2025) AstraZeneca. 

6. Chiesi Completes Clinical Development Program for Carbon-Minimal Pressurized Metered-Dose Inhalers (pMDIs), Paving the Way for Regulatory Submissions (2025) Chiesi. 

7.  GSK announces positive pivotal Phase III data for nextgeneration low carbon version of Ventolin (salbutamol) metered dose inhaler (2025) GSK.